1. Field of Invention
This invention relates to magnetic assemblies, specifically for retaining ferrous materials in the Rumen (upper stomach) of cows to protect the reticulum (lower stomach) and vital organs from Hardware Disease, with high magnetic and physical durability to be reused for other cows or also disassembled for multiple experiments in the science of magnetics.
2. Description of Prior Art
Cows have been known to accidentally eat fencing staples, bailing wire remnants, nails, etc. while grazing. Cow magnets are administered orally to cows to attract and retain ferrous material within the Rumen (upper stomach). The magnetic assembly is heavy enough to prevent passage from the Rumen. The magnetic assembly remains in the Rumen collecting iron particles and retaining them within the Rumen for the entire life of the cow. Retention of sharp iron pieces within the Rumen greatly reduces the possibility of damage to other more delicate, vital organs. Damage to intestines, organs, etc. caused by ingestion of iron objects often causes the animal to stop eating and eventually expire. The cause of death is then categorized as "Hardware Disease."
Heretofore cow magnets have not adequately fulfilled the necessity for the magnet to last more than the lifetime of the cow. Various types of cow magnets have been available over the past thirty years and have contributed greatly to the prevention of Hardware Disease. I will address the following main problems:
(1) Some older designs are made of a magnetically inferior material (Alnico of various grades) which is more subject to demagnetization.
(2) Some older designs are made from Barium Ferrite blocks which are very fragile and could only be magnetized in a direction that caused some sharp long objects to be held dangerously perpendicular to the magnet surface.
(3) The magnetic assembly by Fujisawa U.S. Pat. No. 4,283,698 is the only assembly type cows magnet comparable to the present invention. The Fujisawa Magnet is magnetically proper. Unfortunately it is structurally weak and could be a great danger to the cows. The structural weakness is due to the use of a steel screw to fasten the plastic center rod and the plastic end pieces (See U.S. Pat. No. 4,283,698 FIGS. 1, 2 and 4 detailing components 3 and 3'). In the final stage of the assembly process, as the self tapping screw is inserted into the flat end of the plastic rod, the plastic rod is stressed, stretched, cracked and sometimes stripped out. The use of a steel screw with a weaker material (plastic) thread does not make a secure fastening system for the environment the magnet will be in. Immediate detection of failure of this type is difficult because the actual time of failure can occur after the finished product has been packaged and shipped. The timing of the stress seperation can vary depending upon how tight the screw is and other obvious variables. Excessive rejects due to material fatigue have been found to occur in shipping and after the magnet has been administered to the cows. Failures of the magnet occuring during packaging, shipping, distribution and in the cows can lead to serious consequences. Undetected failures which are administered to the cows and/or failures which occur within the Rumen can, in and of themselves, be the cause of serious damage or death of the animal. There have been many reported structural failures of magnets produced according to the Fujisawa U.S. Pat. No. 4,283,698 both during shipping and after being administered to cows.
This was an unrecognized problem brought to our attention by distributors and end users. Veterinarians and farmers have reported many cases of failed magnets being discovered in pastures after being passed by a cow. Not knowing which animal of the herd has passed the magnet poses two other problems. Which animal to check for injuries and which animal now has no magnet to protect against "Hardware Disease"?
Acids from the stomach loosen and dissolve the small steel screw tightened into plastic which is used to hold the entire Fujisawa U.S. Pat. No. 4,283,698 magnet assembly together. First, when the plastic rod separates, the magnets repel against each other, pushing one or two segments off the end of the rod, exposing the split or broken end of the rod. Second, the loose magnet segments and steel washers form a mass along with the now exposed pointed screw and end cap. Third, the mass now becomes a size and shape that can be passed through the digestive system. The passage of the large mass of magnets, steel washers, broken plastic rods and sharp steel screws can cause blockage of the digestive tract, internal bleeding, and/or piercing of vital organs.
Acids from the stomach can loosen or dissolve the small steel screw which is used to hold the entire Fujisawa U.S. Pat. No. 4,283,698 magnet assembly together. The small steel screw is only 0.107 inches in diameter by 0.750 inches long. An iron nail 0.125 inches in diameter can dissolves 40% in six to twelve months in the cow's Rumen. The black zinc plating used on the small screw will increase the resistance to the acid by four to six times. This means the small steel screw could dissolve in as little as two years and may last as long as six years. This is assuming the plastic lasts this long. Beef cattle may serve their useful lives in the two to six year time frame but, dairy cows are expected to live far beyond the six year life of the small screw.
(4) The standard magnetic configuration adapted for Fujisawa U.S. Pat. No. 4,283,698 on August 1981 is inconistent magnetically from one end to the other. Heretofore, this type of assembly had to be assembled with the magnet segments in the magnetized condition and in a specific order of polarity. Assembling magnets to steel in the repelling sequence required, creates a flux loss from 5 to 10 percent and flux variation from one end to the center of the unit of 25 to 30 percent.
Using the standard holding magnet pattern (steel-magnet-steel-magnet-steel) with the inner steel components having a common polarity, has been a standard practice since early 1960. One evidence of this is the holding magnet design of U.S. Pat. No. 3,014,751 from 1961. The capability of magnetizing this type of magnet assembly after the completion of the assembly process has not heretofore been feasible so cow magnets have been limited to less than optimum magnetic efficiency.
(5) The magnets are magnetized before assembling and force together repelling. U.S. Pat. No. 4,283,698 states under claims 1c "said magnets being arranged such that the magnetic poles of the magnets confronting each other . . . ". This requires one hand to stack the assembly while the other hand keeps it from repelling apart. This requires some training and unnecessary effort. This requires both hands per magnet assembly. This will not lend itself to automated assembly by a vibratory feeder as is common in the industry for other assemblies. To automate the assembly of magnetized magnets is very costly.
(6) There are Four extra pieces in U.S. Pat. No. 4,283,698 (FIG. 4 #2). The two plastic end plates are non-beneficial to the magnetic strength of the assembly. Therefore two extra steel plates per end must be added to complete the magnetic circuit. Plastic end plates are also non-beneficial to the structural integrity. Four extra pieces are also four more places for defects in assembly. Four extra pieces also cost more.
(7) No other applications have been discovered and recommended for the Fujisawa U.S. Pat. No. 4,283,698. It only serves one purpose.